Quantifying Costs Associated with Atopic Dermatitis

■■ Quantifying Costs Associated With Atopic Dermatitis Dear Editor, We read with interest the article by Fivenson and colleagues on the total burden of illness associated with atopic dermatitis. The study is important in that it provides a perspective from payer costs to individual productivity. We agree with their conclusion that atopic dermatitis “imposes a financial burden on the health care system.” Using a claims-based approach that included comorbidities associated with atopic dermatitis and eczema, we estimated direct payer costs within a managed care population to average $580 per patient per year (n=35,000), significantly higher than the $167 per patient per year (n=298) found by Fivenson et al. The difference in annual direct payer cost per patient appears mainly to be the result of different cost-accounting methods. We incorporated costs for comorbid conditions; the validity and accuracy of our use of expert opinion to incorporate disease comorbidities were confirmed in a separate report. It appears that Fivenson et al. included direct costs only if they could be tied directly to atopic dermatitis. Although data in the 2 studies are not directly comparable, direct costs in Fivenson et al. are in the range of those in our study if costs for comorbid conditions that we examined are excluded. Other factors might also explain the disparate results. First, we included patients with eczemas as well as atopic dermatitis; however, we would surmise that the average annual direct payer cost would be even higher than $580 if we restricted our study to patients with atopic dermatitis, which is often chronic and difficult to treat. Second, Fivenson et al. report that 7% to 12% of their patients had severe disease. Yet, a recent report estimates the prevalence of severe disease in atopic dermatitis to be 16% of patients. Therefore, average annual direct costs likely would have been higher if more severe patients were included. Regardless, the study by Fivenson et al. is particularly valuable because it quantified various costs associated with atopic dermatitis including out-of-pocket expenses and productivity. Those costs were obtained by survey of patients and families who, although asked about “eczema,” may not ascribe their time and expenses so specifically; therefore, those costs may, in fact, include the effects of at least some comorbidities. Thus, an annual cost burden of $1,022 per patient with atopic dermatitis may be a conservative total (using our total of $580 for payer direct costs plus the Fivenson et al. total of $442 for out-ofpocket expenses and productivity). In addition, neither study attributes a cost to patients’ decreased quality of life. Thus, we still have not captured completely the financial burden of having atopic dermatitis, which is indeed substantial. Further research will be required to fully understand the burden of illness as well as the cost-effectiveness of patient management and intervention programs.


■■ Quantifying Costs Associated With Atopic Dermatitis
Dear Editor, We read with interest the article by Fivenson and colleagues 1 on the total burden of illness associated with atopic dermatitis. The study is important in that it provides a perspective from payer costs to individual productivity. We agree with their conclusion that atopic dermatitis "imposes a financial burden on the health care system." Using a claims-based approach that included comorbidities associated with atopic dermatitis and eczema, we estimated direct payer costs within a managed care population to average $580 per patient per year (n=35,000), 2 significantly higher than the $167 per patient per year (n=298) found by Fivenson et al. The difference in annual direct payer cost per patient appears mainly to be the result of different cost-accounting methods. We incorporated costs for comorbid conditions; the validity and accuracy of our use of expert opinion to incorporate disease comorbidities were confirmed in a separate report. 3 It appears that Fivenson et al. included direct costs only if they could be tied directly to atopic dermatitis. Although data in the 2 studies are not directly comparable, direct costs in Fivenson et al. are in the range of those in our study if costs for comorbid conditions that we examined are excluded.
Other factors might also explain the disparate results. First, we included patients with eczemas as well as atopic dermatitis; however, we would surmise that the average annual direct payer cost would be even higher than $580 if we restricted our study to patients with atopic dermatitis, which is often chronic and difficult to treat. Second, Fivenson et al. report that 7% to 12% of their patients had severe disease. Yet, a recent report estimates the prevalence of severe disease in atopic dermatitis to be 16% of patients. 4 Therefore, average annual direct costs likely would have been higher if more severe patients were included.
Regardless, the study by Fivenson et al. is particularly valuable because it quantified various costs associated with atopic dermatitis including out-of-pocket expenses and productivity. Those costs were obtained by survey of patients and families who, although asked about "eczema," may not ascribe their time and expenses so specifically; therefore, those costs may, in fact, include the effects of at least some comorbidities. Thus, an annual cost burden of $1,022 per patient with atopic dermatitis may be a conservative total (using our total of $580 for payer direct costs plus the Fivenson et al. total of $442 for out-ofpocket expenses and productivity).
In addition, neither study attributes a cost to patients' decreased quality of life. Thus, we still have not captured completely the financial burden of having atopic dermatitis, which is indeed substantial. Further research will be required to fully understand the burden of illness as well as the cost-effectiveness of patient management and intervention programs.

The Authors Respond
We thank JMCP for the opportunity to comment on the letter by Ellis and colleagues in response to the recent publication of our study. 1 We concur that it is difficult for patients to specifically ascribe their out-of-pocket costs to atopic dermatitis (AD). However, since our study showed that approximately 50% of the total burden of illness associated with AD resulted from days lost from work, it is most important that the patient' s perception of his or her illness, in addition to the health care provider' s perception, be taken into consideration. We admire Ellis et al.' s examination of 35,000 claims and understand their use of comorbidities in their evaluation, especially since one of the most common comorbidities in our population (occurring in approximately 8% of our prospective cohort) was "dermatitis not otherwise specified." However, we, too, examined the population over a 3-year period (n=6,609) and found mean annual per-patient direct expenditures ranging from $123 (in 1995) to $128 (in 1997). Therefore, the $167 per-patient-per-year direct expenditure we found would not appear to be an artifact of our relatively smaller sample size. Certainly, as we have found, it is important to directly query a representative sample of the dataset to gain an understanding of the error inherent in claims analyses. 2 Moreover, we used different insurance systems and not stan-dard costs applied to health care resource use. The Ellis manuscript is not very transparent on how costs were attributed except that a panel determined it. They may have attributed costs to AD/E based on ICD-9 codes other than those we used. Furthermore, we most probably used a different method of assessing severity than the method used in the international study cited. Also, we included individuals with private insurance in our study; thus, our study population probably had different characteristics from the sample used in the ISAAC study. Therefore, it is difficult to compare our findings to those of Ellis et al. Lastly, our previous analyses did attempt to quantitate the effects of this illness on quality of life. 3,4 Indeed, using Pearson correlation coefficients, we found that visit count correlated moderately well with the results of the Dermatology Life Quality Index (r=0.33; P=0.0006).
Taken together, all of our results, in concert with those of Ellis and colleagues, would indeed indicate that AD might impose a significant financial and humanistic burden on society.

■■ Analyses of Cost-Effectiveness of Migraine Therapies Should Consider Multiple Measures Dear Editor,
This letter is in response to the article on the relative cost-effectiveness of triptans by Dr. Adelman and Mr. Belsey that appeared in the January/February 2003 issue of JMCP. 1 I believe their conclusions may be misleading because they are based on an oversimplified analysis of cost-effectiveness.
In order to calculate comparative triptan costs, the authors evaluated only 1 efficacy endpoint: the percentage of patients who were pain-free at 2 hours. Their rationale for focusing on this endpoint alone was that IHS guidelines identify the 2-hour pain-free endpoint as the most important endpoint and that patients have identified complete pain relief as their most important concern. However, patients rate "no recurrence of migraine" almost as high as they rate initial pain relief. 2,3 Furthermore, when doing a cost analysis, there is a need to focus on other endpoints. At a minimum, the total cost of treating a migraine attack for 24 hours (not just 2 hours) should be evaluated. Most patients who have a recurrence of moderate or severe migraine will remedicate with either a repeat dose of triptan or with another medication, thus increasing the overall 24-hour cost.
Recurrence rates from published double-blind studies range from 7% to 47%, depending on the particular triptan and study. 4 The authors, based on an analysis of 2-hour pain-free response rates alone, suggest that rizatriptan (10 mg) is the most cost-effective triptan, but rizatriptan has been associated with recurrence rates in the 35% to 47% range. They also suggest, based on 2-hour pain-free response, that frovatriptan (2.5 mg) is the least cost-effective triptan; however, frovatriptan has lower recurrence rates in the 7% to 25% range.
Migraine recurrence is costly from a number of perspectives. A second or a third dose of a triptan (or other medication) taken within a single 24-hour period increases the "out-of-pocket" medication costs to patients and the reimbursement costs to insurers. Office visits and even emergency room visits may be required for particularly long-lasting, refractory attacks. Employers bear some of the costs from an extended migraine attack in the form of lost productivity. For most migraine sufferers, hours 3 through 24 of the attack (and beyond) can be more costly than the initial 2 hours in terms of both the financial and physical burden of migraine.
Variability in recurrence and remedication rates must be taken into account in order to obtain a reasonable estimate of triptan cost-effectiveness. If a single endpoint is to be used to calculate cost-effectiveness, the 24-hour response endpoint may be most appropriate. The impact of remedication as a result of recurrence is accounted for in measures of 24-hour sustained relief (moderate or severe pain reduced to no or mild pain with no recurrence or remedication within 24 hours) or 24-hour sustained pain freedom (moderate or severe pain reduced to no pain with no recurrence and no remedication). These endpoints